NIST scientists Greg Hoth (left) and Vladislav Gerginov work on NIST-F4, NIST’s new cesium fountain clock. Credit: R. Eskalis/NIST Clocks on Earth are ticking a bit more regularly thanks to NIST-F4, a new atomic clock at the National Institute of Standards and Technology (NIST) campus in Boulder, Colorado.This month, NIST researchers published a journal article establishing NIST-F4 as one of the world’s most accurate timekeepers. NIST has also submitted the clock for acceptance as a primary freq...